It is both costly and time consuming to produce a hologram for display purposes and often once a suitable hologram has been prepared it is required that tens, hundreds and even thousands of copies of this hologram be prepared from it. However, even though the original hologram be bright, copies of it, using the presently employed techniques for copying, yield copy holograms which often are not bright enough when reconstructed using diffuse light. When a large number of copies are required to be prepared from an original transmission hologram it is the common practice to prepare from the transmission hologram a high quality reflection master and then to prepare by contact copying using the reflection master the required number of copies. Thus if a large number of copy holograms are required it is worth expending considerable effort in producing a reflection master from which bright copies can be prepared which are capable of being reconstructed in diffuse light.
We have invented such a reflection master and also a method of preparing this master.